Styphnolobium is a small genus of three or four species of small trees and shrubs in the subfamily Faboideae of the pea family Fabaceae, formerly included within a broader interpretation of the genus Sophora. The species of Styphnolobium differ from Sophora in lacking the ability to form symbioses with rhizobia (nitrogen fixing bacteria) on their roots. They also differ from the related genus Calia (mescalbeans) in having deciduous leaves and flowers in axillary, not terminal, racemes. The leav… (More on Styphnolobium)